Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!rutgers!mephisto!uflorida!novavax!puff!kschnitz
From: kschnitz@puff.UUCP (Kevin Schnitzius)
Newsgroups: comp.software-eng
Subject: Re: structure chart help needed
Message-ID: <73643@puff.UUCP>
Date: 30 Nov 89 18:28:43 GMT
References: <541@sagpd1.UUCP>
Organization: Encore Computer Corp, Fort Lauderdale, FL
Lines: 78

In article <541@sagpd1.UUCP>, jharkins@sagpd1.UUCP (Jim Harkins) writes:
> I'm trying to use a CASE tool to create structure charts for a project 
> being done under the DOD's 2167 spec, and have found a few things that don't
> seem to be addressed in either the CASE documentation nor any books I've got.
> 1.  I had to write some system wide utility routines, in my structure charts
>     I use a library module to represent these.  Then I have separate structure
>     charts for these utilities.  In the structure charts for the library
>     routines should the top module be a library or a regular module?

If it is a library module, it has alread been desgined and implemented for 
ANOTHER system.  All that is needed is the reference to that name and the
particular system and the reader should be able to find out more about the
module.  If you feel it is necessary for clarity to include the library
module in your design, it should be as a regular module (assuming it was 
one the previous system.

> 2.  Modules on the structure charts have data couples going into/out of them.

	[ example of specialized malloc deleted ]

The implemetor who is building your system can choose to use your special 
malloc or not but all that is need is a routine which produces a specific 
object.  This is an implementation detail and NOT a design detail.  There
needs to be enough detail in your design to make the implementor cognizant
of the need of specialize routines when necessary.

>3.  My project is divided into tasks, with a structure chart for each different
>     task.  Communication between tasks is via queues.  In structure chart A
>     it seems I should show message A going to queue A and message B being
>     received from queue B.  In chart B I should show message A being received
>     from queue A and messages being sent to queue B.  But I've never seen
>     a way to show this type of thing in a structure chart.  It seems to me
>     this is pretty important information that shouldn't be forgotten or
>     overlooked.  So how do I do this?  Come to think of it, I've yet to see
>     a way to show queues on structure charts.  The best we've come up with
>     are data only modules, which need to be tricked in order to work properly
>     in this context.

I either show the couple as the whole queue or just an element from the queue.
I have not found a good way to show this.

> 4.  All the books we have around here seem to stop at the point I'm at.
                [...] 
>     I don't want an introduction, I want a thorough treatment of not only
>     what a structure chart is but a good description of how one should look,
>     what kinds of modules/couples/etc go where, and the mechanics of
>     creating them.  A book that does for structure charts what DeMarco's
>     book Structured Analysis and System Specification did for object
>     oriented design.  (We used that book to get this far.)

Personnally, I prefer the Hatley/Pirbhai methodology because I deal with
more realtime problems.  For structure charts, this book recommends:

Page-Jones, Meilir.  The Practical Guide to Structured Systems Design, 2nd
	ed.  Englewood Cliffs, N.J.: Prentice-Hall, 1988.

Yourdon, E. & Constantine, L.  Structured Design: Fundamentals of a Discipline
	of Computer Program and Systems Design.  Englewood Cliffs, N.J.:
	Prentice-Hall, 1975.

Myer, G.  Reliable Software Through Composite Design.  New York: Van Nostrand
	Reinhold, 1975.

> jim
> jharkins@sagpd1
> 
> "Congress. Outside of Zsa Zsa Gabor the most bloated and self indulgent entity
>  in the world."


Good Luck....
-- 
Kevin Schnitzius     (Encore Computer Corporation, Ft. Lauderdale, Florida)
                     (formerly Gould CSD)
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